Video traffic shows signs of hits concentrated on popular videos. Mobile video traffic occupies 70% of total traffic, and a user experiences network congestion due to a heavy increase in the traffic of a mobile communication network. Accordingly, there is a need for a method for effectively delivering video content in a mobile network.
FIG. 1 is a graph illustrating a statistics of video content hits collected by a content supplier according to an embodiment of the related art.
Referring to FIG. 1, popular videos of high 10% in YouTube occupy total traffic of 80% or more.
Accordingly, video traffic related to frequent requests from users needs to be cached in a mobile network. In order to cache such video traffic, there is a need for a method for addressing different issues (e.g., mobility) that are attributable to characteristics when a video cache is used in a mobile network.
Regarding the type of video traffic currently used a lot in the Internet, video is divided into time-based chunks, each of the chunks has a Uniform Resource Locator (URL), and the video is delivered from a content server to a video user, that is, a User Equipment (UE), in such a manner that as the playback time elapses, the UE requests a next chunk using the HyperText Transfer Protocol (HTTP) and the content server delivers a response including the next chunk. Such a chunk-based video delivery method is used by technologies, such as HTTP Live Streaming (HLS) by Apple Inc., Flash video by Adobe Systems Inc., Dynamic Adaptive Streaming over HTTP (DASH) by 3rd Generation Partnership Project (3GPP)/Motion Pictures Expert Group (MPEG), Smooth Streaming by Microsoft Co., and the like. Service providers, such as YouTube and Netflix, use the chunk-based video delivery method.
The structure and operation of a current Evolved Packet Core (EPC) have been designed so that data packets are delivered to the UE through an evolved-NodeB (eNB) via a Public Data Network (PDN) Gateway (P-GW) and a Serving Gateway (S-GW). In a network over which the transmission of data packets starts from an eNB, if an eNB accessed by the UE is changed due to handover, not only a transfer path is changed, but also the start point of the transmission needs to be changed because a cache server or local cache server is included in the eNB. For example, the cache of a Source evolved-NodeB (S-eNB) performs a role of a content server, and when handover occurs, the cache of a Target evolved-NodeB (T-eNB) has to start a role of a content server.
As described above, since the handover method of an EPC has been designed to be suitable for a data path along which data packets are delivered to the UE through an eNB via a P-GW and an S-GW, the handover method normally operates in an environment in which the position of a server is not changed although the UE performs handover.
Accordingly, there is a problem in that data cannot be delivered to the UE using the handover method of an EPC in an environment in which the Content Delivery Network (CDN) server of an existing eNB is no longer accessed due to handover because a cache server, that is, a CDN server, is placed in an eNB.
Furthermore, if data to be delivered is not present in the CDN server of a T-eNB to which the UE has performed handover, service with guaranteed Quality of Experience (QoE) cannot be provided to the UE using a current handover method.
Therefore, a need exists for a method and an apparatus for processing a transmission of content to a UE that has performed handover from an S-eNB to a T-eNB.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.